Hi Aurelie,
The 'wX' appearances are used for 2 related purposes:
- on a group: set the total number of columns inside the group (default number of columns is 4)
- on a question: set the width of a question (default is 1)
In your drawing, you have at most 2 questions that appear to be of equal width. Therefore, you need your group to have 2 columns inside it; you would give it the appearance w2 .
The first question (the year) takes up the full width of the group; therefore it also needs to be 2 columns wide. That, along with the fact it's only taking year input, give an appearance of w2 year (order doesn't matter).
The other questions do not need a wX appearance as they are taking up 1 column width.